Nut torque for header to block?
 

Ok so swapping headers and saw I was missing a nut. Anyone have the proper torque for the nuts?

From the top of my head, I think its ~22 ft/lb. Don't have the service manual handy but I'm almost certain

22 is what my Borla instructions said. I did 24

I found a lot of mis-information in the borla instructions. I used them to aid in my rev works install but they either had a lot of typo's or just didn't know the proper bolt sizing.

I tightened mine up to 22 but I think I'm going to go 24 as well today.

How important is it to torque up the header bolts?

It's important if you don't want any leaks... then check and retorque them a week or something later after it's fully heat cycled and settled in.

Based on 22ft lb of torque. It isn't much, so isn't that almost hand tight + max of half a turn more?

Proper torque is important so there will not be any warped flanges or leaks. Try to borrow or purchase a torque wrench.

Based solely on my own experience with other engines 22lb/ft 30nm seems reasonable. That's a lot more than hand tight + half a turn. Just do em all then go back and check em again. Gasket squish will lower the original torque on the first couple.

I'm not sure why you'd need to go back a week later. I've put on thousands of them over the years and never had one come lose a week or even a year later, that I know of.

22lb/ft then re-torque after a few heat cycles

Flange and gaskets can tend to loosen/move around a bit after a few heat cycles.